So how do Portland police Cold Case detectives know Mark was murdered? By looking at the clues from that summer weekend, evidence that investigators say point to a violent death. It begins on the second of July, when the 42-year-old North Portland man called the air freight department for United Airlines at Portland International Airport where he worked, saying he needed the night off for a personal emergency.

'A friend actually reported him missing on the sixth, which would have been Tuesday. And then, Port of Portland police actually went to his house that day to check because he hadn't shown up for work. And the evidence starts becoming apparent. There was a substantial amount of evidence in the house,' says Stahlman.

Fox 12 reporter Nicole Doll has spent weeks talking to Portland police Cold Case Division detectives about their unsolved cases and going through the files. Her stories are being run every Thursday on the 10 O'clock News in hopes the public can help solve them. This one was broadcast on Nov. 3.

Crime scene photos show that someone had cleaned up biological evidence blood splatter - all over the walls of Mark's home on Northeast 137th Avenue. His 1995 Ford Explorer Sport was also missing. It was found two weeks later near Southeast 43rd Avenue and Division Street, an area investigators say Dribin didn't frequent.

According to Mark's father Ken and his brother Terry, the slow pace of the investigation has been torture on the family.

'You know the biggest loss a person can have is losing a child and under these circumstances, with no closure, no justice, no anything, it take its toll on all three of us, my wife, Terry and myself,' says Ken Dribin.

Mark Dribin was last seen that Saturday at what was then the Eagle Tavern, a bar on Southwest 13th Avenue and Burnside Street. After that, the trail goes cold and his body has never been recovered.

Investigators are look for any tip to help solve the case.

'Where his body was dumped and the condition it was dumped. The materials that are around the body. That type of thing. They can all lead to a suspect,' says Stahlman.

Detectives would like to talk to anyone who saw Mark or his SUV around the time he vanished. As for his family, they'll keep waiting, trying to focus on how they remember him, not the uncertainty of his disappearance.

'He was just a great son,' says Ken Dribin.

If you have any information about the case, call crimestoppers, 503-823-help (4357). A $1,000 reward is available and you can remain anonymous.

On next week's Fox 12's Most Wanted Cold Case Homicide Unit series, the 1995 unsolved murder of a 61-year man. Police say Bing Joe was murdered during a robbery in Chinatown. And while investigators say witnesses saw the killers, no arrests have ever been made.